The present invention relates to the field of fly pest control in the production of mushrooms, and more particularly to thermophilic, spore forming bacteria and supplements for the control of dipteran pests in the production of high quality mushroom crops.
The commercial production of mushrooms is a major commercial industry throughout many parts of the world. For example, the production of the commercial mushroom Agaricus bisporus in the United States was valued at $777 million in 1996-1997. The control of fly pests, Diptera, is an important component of producing high yielding, quality crops of such mushrooms. Unfortunately, the reliable control of such pests has been complicated by the development of resistance to pesticides, toxicity of pesticides to mushroom mycelium, persistent pesticide residues in the compost/casing material and concerns about exposure of workers to toxic pesticides. Consequently, new types of pesticide preparations and methods of application are necessary for the continued production of commercial mushrooms.
Lycoriella mali (xe2x80x9cL. malixe2x80x9d) (Diptera:Sciaridae) is a major insect pest in the commercial production of mushrooms in the United States, Canada, Asia and Australia. L. mali is capable of reducing mushroom production by 85-90% in the absence of larvicides and adulticides. While the damage caused by first generation larvae is generally inconsequential, the production of mature fruiting bodies may be significantly affected by second generation larvae actively feeding on the developing mushroom primordia. Additional generations of L. mali may develop during the six week cyclic harvesting period, further affecting the production of mushrooms. In addition, adult flies can be a significant factor in the spread of a number of mushroom diseases including Verticillium fungicola, Pseudomonas tolassi and Trichoderma harzianum. The control of adult L. mali is thus important to prevent additional oviposition and mechanical transmission of mushroom pathogens.
The infestation of adult L. mali flies generally occurs as the compost cools and during the introduction of spawn into the compost. Female flies oviposit in the compost and the developing larvae feed actively on the compost and the developing mycelium of the mushroom crop. When the casing layer is applied, the larvae may move into this layer to continue feeding on the developing mycelium. As mushroom fruiting bodies begin to develop, the first generation of flies derived from the oviposition begin to emerge. These first generation flies mate and lay additional eggs in the compost and casing layers. Larvae from these eggs will feed on the mycelium. In high numbers, this second as well as subsequent generations of larvae will damage mushroom primordia and tunnel into the stipes of maturing mushrooms.
Current methods of controlling L. mali and other fly pests include the use of larvicides and adulticides. Commonly used larvicides include diflubenzuron, cyromazine and methoprene while permethrin and dichlorvos are popular for use as adulticides. However, various problems can be associated with the use of larvicides and adulticides. For example, the larvicide methoprene is only effective against first generation larvae, while larvae have developed resistance to diflubenzuron as well as many adulticides in current use. It has been estimated that L. mali can reduce mushroom yields by about 20% with the current pesticide applications in use.
Certain studies have experimented with the thermophilic, spore forming bacteria Bacillus thuringiensis var. israelensis (xe2x80x9cBTixe2x80x9d) for the control of L. mali. For example, it has been demonstrated that a liquid formulation of BTi sold as Vectobac 12AS (Abbott Laboratories, Inc.) can be effective in controlling larval populations of L mali when applied to compost and casing in commercial mushroom houses. However, these applications require large amounts of water to insure adequate mixing of the BTi formulation in both the compost and casing. These aqueous applications prove difficult to incorporate into growing strategies. In addition, the cost of Vectobac, developed primarily for applications in water for control of public health pests, is high. Liquid BTi, thus, is not viewed as acceptable by commercial mushroom producers. There is a need of the development of new methods of controlling fly pests and the production of quality crops in high yields.
The present invention generally relates to the control of fly pests for improved mushroom production. The present invention relates to preparations comprising mushroom spawn, mushroom compost and thermophilic, spore forming bacteria. The present invention also relates to preparations comprising thermophilic, spore forming bacteria and mushroom casing materials. The invention also relates to preparations comprising supplement combined with thermophilic, spore forming bacteria. Additionally, the invention provides methods of using the preparations of the present invention for the control of fly pests and the improved production of mushroom crops.